Use optimized scrolling for pepper plugins.

webkit/glue/plugins/pepper_plugin_instance.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WEBKIT_GLUE_PLUGINS_PEPPER_PLUGIN_INSTANCE_H_
 #define WEBKIT_GLUE_PLUGINS_PEPPER_PLUGIN_INSTANCE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 82 matching lines @@
   void Paint(WebKit::WebCanvas* canvas,
              const gfx::Rect& plugin_rect,
              const gfx::Rect& paint_rect);
 
   // Schedules a paint of the page for the given region. The coordinates are
   // relative to the top-left of the plugin. This does nothing if the plugin
   // has not yet been positioned. You can supply an empty gfx::Rect() to
   // invalidate the entire plugin.
   void InvalidateRect(const gfx::Rect& rect);
 
+  // Schedules a scroll of the plugin.  This uses optimized scrolling only for
+  // full-frame plugins, as otherwise there could be other elements on top.  The
+  // slow path can also be triggered if there is an overlapping frame.
+  void ScrollRect(int dx, int dy, const gfx::Rect& rect);
+
   // PPB_Instance implementation.
   PP_Var GetWindowObject();
   PP_Var GetOwnerElementObject();
   bool BindGraphics(PP_Resource device_id);
   bool full_frame() const { return full_frame_; }
   bool SetCursor(PP_CursorType_Dev type);
   PP_Var ExecuteScript(PP_Var script, PP_Var* exception);
 
   // PPP_Instance pass-through.
   void Delete();
@@ skipping 155 matching lines @@
 
   // Plugin container for fullscreen mode. NULL if not in fullscreen mode.
   FullscreenContainer* fullscreen_container_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginInstance);
 };
 
 }  // namespace pepper
 
 #endif  // WEBKIT_GLUE_PLUGINS_PEPPER_PLUGIN_INSTANCE_H_